1. Field of the Invention
The invention relates to a flexible line element, particularly for exhaust pipes of internal combustion engines of motor vehicles.
2. Description of the Prior Art
Flexible line elements arc e.g. incorporated as adaptors into the exhaust pipe of a motor vehicle, which is installed on the vehicle floor, in order to absorb movements and vibrations and prevent the transfer thereof to adjacent components, such as arise due to elastically mounted driving engines, vehicle faults, temperature-caused length changes, etc. They generally comprise a helically or annularly corrugated metal bellows, together with further elements, such as line and/or support elements, together with additional elements for supporting and/or increasing stability, e.g. metal gauze, or damping elements, so that if vibrations are excited in the resonant frequency range of the bellows movement increases of the latter are prevented, because they could lead to a reduction of the service life and to interaction with other components for noise production purposes.
In many cases flexible line elements of this type are exposed to torsional stresses. If the bellows of such line elements has a torsion-stiff construction, such as e.g. a parallel bellows, although such torsional stresses do not lead to its failure, they are transferred in undesired manner to adjacent components. If the bellows is torsion-soft, it is suitable for the decoupling of adjacent components, but in particular dynamic torsional stresses can lead to its failure. It is stressed in this connection that in the case of dynamic stressing a metallic material is subject to earlier fatigue than with static stressing, the stresses to which a line element in the exhaust pipe of a vehicle is exposed being more particularly of a dynamic nature.
Thus, on the basis of a line element of the aforementioned type, one object of the invention is to provide a line element that is compact and especially may have short axial extension. A further object of the invention is to provide the line element on the one hand to be torsion-soft, so that it does not transfer torsional stresses to adjacent components, but on the other that the line element does not fail when high torsional stresses occur.